Dynamical friction and the evolution of satellites in virialized halos: the theory of linear response

The evolution of a small satellite inside a more massive truncated isothermal spherical halo is studied using both the Theory of Linear Response for dynamical friction and N-Body simulations. The analytical approach includes the effects of the gravitational wake, of the tidal deformation and the shift of the barycenter of the primary, so unifying the local versus global interpretation of dynamical friction. Sizes, masses, orbital energies and eccentricities are chosen as expected in hierarchical clustering models. We find that in general the drag force in self-gravitating backgrounds is weaker than in uniform media and that the orbital decay is not accompanied by a significant circularization. We also show that the dynamical friction time scale is weakly dependent on the initial circularity. We provide a fitting formula for the decay time that includes the effect of mass and angular momentum loss. Live satellites with dense cores can survive disruption up to an Hubble time within the primary, notwithstanding the initial choice of orbital parameters. Dwarf spheroidal satellites of the Milky Way, like Sagittarius A and Fornax, have already suffered mass stripping and, with their present masses, the sinking times exceed 10 Gyr even if they are on very eccentric orbits.Comment: 27 pages including 9 figures. Accepted for publication in the Astrophysical Journal. Part 2, issue November 10 1999, Volume 52

Accretion of a satellite onto a spherical galaxy. II. Binary evolution and orbital decay

We study the dynamical evolution of a satellite orbiting outside of a companion spherical galaxy. The satellite is subject to a back-reaction force resulting from the density fluctuations excited in the primary stellar system. We evaluate this force using the linear response theory developed in Colpi and Pallavicini (1997). The force is computed in the reference frame comoving with the primary galaxy and is expanded in multipoles. To capture the relevant features of the physical process determining the evolution of the detached binary, we introduce in the Hamiltonian the harmonic potential as interaction potential among stars. The dynamics of the satellite is computed self-consistently. We determine the conditions for tidal capture of a satellite from an asymptotic free state. If the binary comes to existence as a bound pair, stability against orbital decay is lost near resonance. The time scale of binary coalescence is computed as a function of the eccentricity and mass ratio. In a comparison with Weinberg's perturbative technique we demonstrate that pinning the center of mass of the galaxy would induce a much larger torque on the satellite.Comment: 13 pages, Tex,+ 10 .ps figures Submitted to The Astrophysical Journa

Crohn’s Disease Increases the Mesothelial Properties of Adipocyte Progenitors in the Creeping Fat

Malaltia de Crohn; Teixit adipós; MesoteliEnfermedad de Crohn; Tejido adiposo; MesotelioCrohn’s disease; Adipose tissue; MesotheliumOur understanding of the interplay between human adipose tissue and the immune system is limited. The mesothelium, an immunologically active structure, emerged as a source of visceral adipose tissue. After investigating the mesothelial properties of human visceral and subcutaneous adipose tissue and their progenitors, we explored whether the dysfunctional obese and Crohn’s disease environments influence the mesothelial/mesenchymal properties of their adipocyte precursors, as well as their ability to mount an immune response. Using a tandem transcriptomic/proteomic approach, we evaluated the mesothelial and mesenchymal expression profiles in adipose tissue, both in subjects covering a wide range of body-mass indexes and in Crohn’s disease patients. We also isolated adipose tissue precursors (adipose-derived stem cells, ASCs) to assess their mesothelial/mesenchymal properties, as well as their antigen-presenting features. Human visceral tissue presented a mesothelial phenotype not detected in the subcutaneous fat. Only ASCs from mesenteric adipose tissue, named creeping fat, had a significantly higher expression of the hallmark mesothelial genes mesothelin (MSLN) and Wilms’ tumor suppressor gene 1 (WT1), supporting a mesothelial nature of these cells. Both lean and Crohn’s disease visceral ASCs expressed equivalent surface percentages of the antigen-presenting molecules human leucocyte antigen—DR isotype (HLA-DR) and CD86. However, lean-derived ASCs were predominantly HLA-DR dim, whereas in Crohn’s disease, the HLA-DR bright subpopulation was increased 3.2-fold. Importantly, the mesothelial-enriched Crohn’s disease precursors activated CD4+ T-lymphocytes. Our study evidences a mesothelial signature in the creeping fat of Crohn’s disease patients and its progenitor cells, the latter being able to present antigens and orchestrate an immune response.This work was supported by grants from the Spanish Ministry of Science, Innovation and Universities (PI14/00228 and PI17/01503 to JV, SAF2015-65019-R to SF-V, BFU2015-70454-REDT and BFU2017-90578-REDT to SF-V and MMM, BFU2016-76711-R to MMM and PI15/00143 and PI18/00037 to CS) co-financed by the European Regional Development Fund (ERDF) and by Fundació La Marató de TV3 (PV170125) to SF-V and the European Crohn’s and Colitis Organization (ECCO) grant to CS. The Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM) (CB07708/0012) is an initiative of the Instituto de Salud Carlos III. AM is a recipient of a postdoctoral fellowship from FJCI-2014-23060 and IJCI-2016-30572. SF-V acknowledges support from the Miguel Servet tenure-track program (CP10/00438 and CPII16/00008) of the Fondo de Investigación Sanitaria, co-financed by the ERDF. C.S. acknowledges support from the ‘Ramón y Cajal’ program from MINECO (RYC2013-13186), co-financed by the ERDF

Evolution of the Dark Matter Phase-Space Density Distributions of LCDM Halos

We study the evolution of phase-space density during the hierarchical structure formation of LCDM halos. We compute both a spherically-averaged surrogate for phase-space density (Q) and the coarse-grained distribution function f(x,v) for dark matter particles that lie within~2 virial radii of four Milky-Way-sized dark matter halos. The estimated f(x,v) spans over four decades at any radius. Dark matter particles that end up within two virial radii of a Milky-Way-sized DM halo at $z=0$ have an approximately Gaussian distribution in log(f) at early redshifts, but the distribution becomes increasingly skewed at lower redshifts. The value corresponding to the peak of the Gaussian decreases as the evolution progresses and is well described by a power-law in (1+z). The highest values of f are found at the centers of dark matter halos and subhalos, where f can be an order of magnitude higher than in the center of the main halo. The power-law Q(r) profile likely reflects the distribution of entropy (K = sigma^2/rho^{2/3} \propto r^{1.2}), which dark matter acquires as it is accreted onto a growing halo. The estimated f(x, v), on the other hand, exhibits a more complicated behavior. Although the median coarse-grained phase-space density profile F(r) can be approximated by a power-law in the inner regions of halos and at larger radii the profile flattens significantly. This is because phase-space density averaged on small scales is sensitive to the high-f material associated with surviving subhalos, as well as relatively unmixed material (probably in streams) resulting from disrupted subhalos, which contribute a sizable fraction of matter at large radii. (ABRIDGED)Comment: Closely matches version accepted for publicatio

Highly informative SSR genotyping reveals large genetic diversity and limited differentiation in European larch (Larix decidua) populations from Romania

[EN] European larch (Larix decidua) is naturally distributed at high elevations in Central Europe. Romanian populations of L. decidua are scattered in different areas of the country. In this study, we used 12 highly informative genomic simple sequence repeat (SSR) markers for genotyping seven populations from different areas of Romania. The SSR markers were highly variable, with up to 11 alleles per SSR locus and an average polymorphic information content of 0.713. High values of observed (Ho = 0.542) and expected (He = 0.738) heterozygosities were observed. Cluster analysis of populations did not group them according to geographical distance, but some clusters contained populations from a similar altitudinal range. The partition of genetic variation revealed that two-thirds of the genetic variation was found within individuals (due to high Ho levels), while only one-sixth of the total genetic variation corresponded to variation among populations. A population structure analysis identified four genetic clusters, and in most cases individuals from a single population were assigned to several genetic clusters. Multivariate principal coordinates analysis confirmed the population structure analysis. SSR markers are a powerful tool for evaluating diversity, relationships, and the genetic structure of Romanian L. decidua populations, which have high levels of diversity and low genetic structurationPietro Gramazio is grateful to Universitat Politecnica de Valencia for a predoctoral contract (Programa FPI de la UPV-Subprograma 1/2013 call). Ioana M Plesa is grateful to the Doctoral School of the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca and ICHAT - Institute of Advanced Horticulture Research of Transylvania, and Universitat Politecnica de Valencia, for their support. Mariola Plazas is grateful to Spanish Ministerio de Economia, Industria y Competitividad for a post doctoral grant within the Juan de la Cierva programme (FCJI-2015-24835).Gramazio, P.; Plesa, IM.; Truta, AM.; Sestras, AF.; Vilanova Navarro, S.; Plazas Ávila, MDLO.; Vicente, O.... (2018). Highly informative SSR genotyping reveals large genetic diversity and limited differentiation in European larch (Larix decidua) populations from Romania. Turkish Journal of Agriculture and Forestry. 42(3):165-175. https://doi.org/10.3906/tar-1801-41S16517542

The Metamorphosis of Tidally Stirred Dwarf Galaxies

We present results from high-resolution N-Body/SPH simulations of rotationally supported dwarf irregular galaxies moving on bound orbits in the massive dark matter halo of the Milky Way.The dwarf models span a range in disk surface density and the masses and sizes of their dark halos are consistent with the predictions of cold dark matter cosmogonies. We show that the strong tidal field of the Milky Way determines severe mass loss in their halos and disks and induces bar and bending instabilities that transform low surface brightness dwarfs (LSBs) into dwarf spheroidals (dSphs) and high surface brightness dwarfs (HSBs) into dwarf ellipticals (dEs) in less than 10 Gyr. The final central velocity dispersions of the remnants are in the range 8-30 km/s and their final $v/\sigma$ falls to values $< 0.5$, matching well the kinematics of early-type dwarfs. The transformation requires the orbital time of the dwarf to be \simlt 3-4 Gyr, which implies a halo as massive and extended as predicted by hierarchical models of galaxy formation to explain the origin of even the farthest dSph satellites of the Milky Way, Leo I and Leo II. Only dwarfs with central dark matter densities as high as those of Draco and Ursa Minor can survive for 10 Gyr in the proximity of the Milky Way: this is naturally achieved within hierarchical models, where the densest objects should have small orbital times due to their early formation epochs. Part of the gas is stripped and part is funneled to the center due to the bar, generating one strong burst of star formation in HSBs and smaller, multiple bursts in LSBs. Extended low-surface brightness stellar and gaseous streams originate from LSBs and, when projected along the line of sight, can lead to overestimate the mass-to-light ratio of the bound remnant by a factor \simlt 2,Comment: 29 pages, 34 figures, submitted to ApJ. Figures 5,11 and 32 are given as separate GIF files. Other figures and the movies of the simulations can be found at http://pcblu.mib.infn.it/~lucio/LG/LG.htm

Scientific collaboration for early detection of invaders results in a significant update on estimated range: lessons from Stenothoe georgiana Bynum & Fox 1977

Detection of new non-indigenous species is often delayed when taxonomically challenging taxa are involved, such as small-sized marine organisms. The present study highlights the relevance of scientific cooperation in the early detection of the invader amphipod Stenothoe georgiana. Originally described from North Carolina (USA), the species was recently found in Chile and the Western Mediterranean. Here, we provide the first record of the species in Macaronesia, Atlantic coasts of continental Europe, North Africa and Australia, and extend its known distribution along the Mediterranean coast. Just like other small crustaceans, shipping (including recreational boating) and aquaculture are probably the main vectors of introduction and secondary spread for this amphipod species. This case of S. georgiana sheds light on the importance of promoting taxonomical knowledge, and building multidisciplinary expertise networks that ensure an effective spread of alien species information. We also encourage the implementation of standardized monitoring methodologies to facilitate early detection of small mobile invaders

Influence Analysis in Consensus Search - A Multi Criteria Group Decision Making Approach in Environmental Management

The environmental decision problems often are divisive, even in a technical realm, decision makers with strong personalities influence outcomes. The purpose of this study is to define and quantify the factors that affect the conservation objectives of a national natural park located in Colombia, South America adding the judgments of six decision makers with different knowledge (every decision maker is also a stakeholder representative). This paper uses a hybrid multiple criteria group decision making model (MCDM), combining the social network analysis (SNA), analytic hierarchy process (AHP) and similarity measures to solve the consensus and anchoring problem among environmental decision makers. The SNA technique is used to build an influential network relation map among decision makers and to obtain their weights for applying a weighted analytic hierarchy process. Then, the final decision matrices for every decision maker are compared between them in order to identify the consensus level of the problem.Romero Gelvez, JI.; García Melón, M. (2016). Influence Analysis in Consensus Search - A Multi Criteria Group Decision Making Approach in Environmental Management. International Journal of Information Technology and Decision Making. 15(4):791-813. doi:10.1142/S0219622016400034S791813154Regan, H. M., Colyvan, M., & Markovchick-Nicholls, L. (2006). A formal model for consensus and negotiation in environmental management. Journal of Environmental Management, 80(2), 167-176. doi:10.1016/j.jenvman.2005.09.004Reed, M. S. (2008). Stakeholder participation for environmental management: A literature review. Biological Conservation, 141(10), 2417-2431. doi:10.1016/j.biocon.2008.07.014Gomez-Navarro, T., & Garcia-Melon, M. (2011). DESIGN OF AN EFFICIENCY INDEX FOR THE RANK ORDER OF SOIL REMEDIATION TECHNIQUES. Environmental Engineering and Management Journal, 10(5), 603-613. doi:10.30638/eemj.2011.083Aragonés-Beltrán, P., García-Melón, M., & Estruch-Guitart, V. (2015). ANALYSIS OF THE PARTICIPATION OF STAKEHOLDERS IN ENVIRONMENTAL MANAGEMENT BASED ON ANP: APPLICATION TO A SPANISH NATURAL PARK. International Journal of the Analytic Hierarchy Process, 7(1). doi:10.13033/ijahp.v7i1.276Belton, V., & Stewart, T. J. (2002). Multiple Criteria Decision Analysis. doi:10.1007/978-1-4615-1495-4Ginevičius, R., & Podvezko, V. (2009). EVALUATING THE CHANGES IN ECONOMIC AND SOCIAL DEVELOPMENT OF LITHUANIAN COUNTIES BY MULTIPLE CRITERIA METHODS. Technological and Economic Development of Economy, 15(3), 418-436. doi:10.3846/1392-8619.2009.15.418-436Ramzan, N., Degenkolbe, S., & Witt, W. (2008). Evaluating and improving environmental performance of HC’s recovery system: A case study of distillation unit. Chemical Engineering Journal, 140(1-3), 201-213. doi:10.1016/j.cej.2007.09.042Sólnes, J. (2003). 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S., Graves, A., Dandy, N., Posthumus, H., Hubacek, K., Morris, J., … Stringer, L. C. (2009). Who’s in and why? A typology of stakeholder analysis methods for natural resource management. Journal of Environmental Management, 90(5), 1933-1949. doi:10.1016/j.jenvman.2009.01.001Bonner, B. L., & Bolinger, A. R. (2013). Separating the confident from the correct: Leveraging member knowledge in groups to improve decision making and performance. Organizational Behavior and Human Decision Processes, 122(2), 214-221. doi:10.1016/j.obhdp.2013.07.005Kirchler, E., & Davis, J. H. (1986). The influence of member status differences and task type on group consensus and member position change. Journal of Personality and Social Psychology, 51(1), 83-91. doi:10.1037/0022-3514.51.1.83Sniezek, J. A., & Henry, R. A. (1989). Accuracy and confidence in group judgment. Organizational Behavior and Human Decision Processes, 43(1), 1-28. doi:10.1016/0749-5978(89)90055-1Bonner, B. L., Sillito, S. D., & Baumann, M. R. (2007). Collective estimation: Accuracy, expertise, and extroversion as sources of intra-group influence. Organizational Behavior and Human Decision Processes, 103(1), 121-133. doi:10.1016/j.obhdp.2006.05.001Burgman, M. (2005). Risks and Decisions for Conservation and Environmental Management. doi:10.1017/cbo9780511614279Mitchell, R. K., Agle, B. R., & Wood, D. J. (1997). Toward a Theory of Stakeholder Identification and Salience: Defining the Principle of who and What Really Counts. Academy of Management Review, 22(4), 853-886. doi:10.5465/amr.1997.9711022105Bryson, J. M. (2004). What to do when Stakeholders matter. Public Management Review, 6(1), 21-53. doi:10.1080/14719030410001675722Biggs, S., & Matsaert, H. (1999). An actor-oriented approach for strengthening research and development capabilities in natural resource systems. Public Administration and Development, 19(3), 231-262. doi:10.1002/(sici)1099-162x(199908)19:33.0.co;2-eWu, J., & Chiclana, F. (2014). 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An optical coherence tomography-based grading of diabetic maculopathy proposed by an international expert panel: The European School for Advanced Studies in Ophthalmology classification.

Aims:To present an authoritative, universal, easy-to-use morphologic classification of diabetic maculopathy based on spectral domain optical coherence tomography.Methods:The first draft of the project was developed based on previously published classifications and a literature search regarding the spectral domain optical coherence tomography quantitative and qualitative features of diabetic maculopathy. This draft was sent to an international panel of retina experts for a first revision. The panel met at the European School for Advanced Studies in Ophthalmology headquarters in Lugano, Switzerland, and elaborated the final document.Results:Seven tomographic qualitative and quantitative features are taken into account and scored according to a grading protocol termed TCED-HFV, which includes foveal thickness (T), corresponding to either central subfoveal thickness or macular volume, intraretinal cysts (C), the ellipsoid zone (EZ) and/or external limiting membrane (ELM) status (E), presence of disorganization of the inner retinal layers (D), number of hyperreflective foci (H), subfoveal fluid (F), and vitreoretinal relationship (V). Four different stages of the disease, that is, early diabetic maculopathy, advanced diabetic maculopathy, severe diabetic maculopathy, and atrophic maculopathy, are based on the first four variables, namely the T, C, E, and D. The different stages reflect progressive severity of the disease.Conclusion:A novel grading system of diabetic maculopathy is hereby proposed. The classification is aimed at providing a simple, direct, objective tool to classify diabetic maculopathy (irrespective to the treatment status) even for non-retinal experts and can be used for therapeutic and prognostic purposes, as well as for correct evaluation and reproducibility of clinical investigations